When connecting a Roku Express+ player to multiple TV's i.e. both HDMI and A/V inputs are used, the Roku UI becomes permanently distorted/unusuable at an odd resolution. However, this occurs only when 4:3 display is used with the A/V connection and 16:9 with the HDMI. Selecting channels such as SlingTV on the Roku remote works perfectly and the channel seems to auto-configure the proper resolution based on the device connection. The Roku Home Screen and sub-sections of the user interface does not seem to know what is going on and renders an unnavigable interface resolution. The reason I have my Roku set up with two devices is because I have a wall-mounted TV for watching while in sofa-bed mode and another TV on a floor-stand for watching sports and such in regular couch-potato mode. My TV with the HDMI connection is at 1080p, while the one with the A/V connection is at 480p as it is quite older/smaller. Not sure what causes the interface to bug out, but Roku Channels don't seem to have an issue with this themselves if you don't exit them or just use the ones for access on the remote.
Also, switching back to the default TV or the one prior to causing the interface to bug out won't actually undo any of what happened. I have to manually reboot the Roku by unplugging it from the wall outlet.
Seems like forcing my 480p tv to use 16:9 resolution in the Roku fixes it.